Laser Capture Microdissection (“LCM”) is an established technology used to pluck out tumor cells, or other types of cells, from a heterogeneous piece of tissue under direct microscopic visualization. The procured cells are used in commercial diagnostic assays, clinical trials, and research studies by pharma and academia. LCM is used by thousands of scientists worldwide. The most popular, and most useful, form of LCM employs a laser beam or a source of radiation to heat a flat plastic film that is held against the slice of tissue mounted on a glass slide (FIG. 1A). The plastic film is uniformly impregnated with a dye that absorbs laser energy. The region of the plastic film positioned over the tissue region or cell of interest is selectively heated by the radiation causing this region to melt and embed itself into the tissue segment immediately underneath (FIG. 1B). When the film is lifted off the tissue the portions of the tissue adherent to the undersurface of the film are ripped free of the tissue section (e.g., see Espina V., et al. (2006) Nature Prot. 1(2):586-603).
Despite the power and utility of LCM, the method is currently limited by a number of shortcomings. First, currently available LCM methods suffer from the variability in the capture efficiency of the desired region of the tissue. The variability is caused by a reduced adhesive force on the top of the tissue section between the tissue and the film and an increased adhesive force between the tissue section and the glass slide substratum. Second, the resolution of LCM systems is limited because the film melts against the tissue in a variable manner depending on the focus of the laser beam, the surface contours, and the wavelength of the light. An area spanning many tissue cell diameters is often captured, thus limiting the resolution and preventing the precise capture of single cells or components of cells.
Despite advances in methods and composition pertaining LCM, there remain significant drawbacks to the methods which limit the use and application of LCM. These needs and other needs are satisfied by the present disclosure.